Papers

Behavioural responses of Sandwich terns following the construction of offshore wind farms

GPS tracking sheds light on the ‘barrier effects’ of offshore wind farms, where renewable energy developments may act as obstacles that impede the movements of seabirds to and from their colonies during the breeding season, or on migration. Between 2016 and 2019, BTO scientists fitted Sandwich Terns breeding at Scolt Head Island in Norfolk with long-life GPS tags which tracked the birds’ movements over multiple years. When the research began, there were five operational offshore wind farms within the distance that Sandwich Terns are known to fly on foraging trips. Two more offshore wind farms were under construction, and became operational during the course of the study. The results revealed that Sandwich Terns entered offshore wind farms, but the extent to which they used these areas varied over time and between sites. For the two wind farms that were completed during the study, there was a marked reduction in the amount of time birds spent at these sites between the first and second year of operation. Although birds sometimes entered offshore wind farms while foraging, they appeared to avoid them when commuting between foraging areas and their colony. This created an apparent ‘funnelling’ effect between important feeding locations. The changes found could be driven by changes to the birds’ sandeel prey distribution, avoidance of wind farms, or changes in airflow patterns following wind farm construction. The study shows that the responses of seabirds to offshore wind farms are many and complex. Further research is needed to fully understand the nature of these interactions, at a time when ever more wind farms are being constructed to mitigate the impacts of climate change.

17.01.24

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Natural body size variation in seabirds provides a fundamental challenge for flight height determination by single-camera photgrammetry. A comment on Humphries et al. 2023

Determining flight heights for seabirds is a crucial prerequisite for understanding collision risks associated with offshore wind farms, but obtaining these can be challenging. This comment addresses concerns over the workflow proposed by Humphries et al. (2023).

15.01.24

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Extended molt phenology models improve inferences about molt duration and timing

Moult is an essential but understudied life-history event in birds, and one that is difficult to study with current statistical approaches. This paper presents an extended modelling framework that should remove barriers to modelling the phenology of moult.

14.01.24

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Remote tracking unveils intercontinental movements of nomadic Short-eared Owls Asio flammeus with implications for resource tracking by irruptive specialist predators

Birds may exhibit a range of different movement patterns, from the dispersal that takes them away from the nest in which they were raised, through to annual migrations between breeding and wintering areas located thousands of miles apart. Some of these movements are more difficult to study than others, and this is particularly true for those species that are nomadic in their behaviour. International research led by BTO has revealed that Short-eared Owls make astonishing nomadic migrations between nest sites as far apart as Scotland and Arctic Russia.

11.01.24

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